value quality siderealorsynodic author ref method 6.0310 2 Synodic Erasmus 2020ApJS..247...13E Lightcurve 6.0312 2 Synodic Pal 2020ApJS..247...26P Lightcurve 6.0321 2 Sidereal Durech 2020A&A...643A..59D Model